A Study on the Safety and Immune Response of Investigational COVID-19 mRNA Vaccines in Healthy Adults

NCT05960097 | Completed Phase 2 Results DMC FDA Drug

• 1 other identifier: 219075
• Study Type: interventional
• Target: 692
• Locations: 2 countries
• Sites: 17

Brief Summary

The purpose of Part A of this study is to assess the immune response and safety of a booster dose of investigational COVID-19 mRNA vaccines in healthy adults. The study will compare the investigational vaccines to control vaccine. The purpose of Part B of this study is to assess the immune response and safety of a booster dose of investigational COVID-19 mRNA vaccines in healthy adults. The study will compare the investigational vaccine under three different storage conditions.

Conditions

SARS-CoV-2; COVID-19

Keywords

COVID-19; Pandemic; Booster vaccine

Outcome Measures

Primary Outcomes (11)

• Part A: Geometric Mean Titer (GMT) of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

  At Day 29

• Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

  At Day 29

• Part B: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

  At Day 29

• Part A: Number of Participants Reporting Any Solicited Administration Site Adverse Events (AEs)

  Assessed solicited administration site events included injection site redness (erythema), pain, swelling and lymphadenopathy (defined as localized axillary, cervical or supraclavicular swelling or tenderness ipsilateral to the injection arm). Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 7

• Part A: Number of Participants Reporting Any Solicited Systemic AEs

  Assessed solicited systemic events included fever, chills, headache, myalgia (muscle pain), arthralgia (joint pain), and fatigue (tiredness). Fever is defined as body temperature is higher than or equal to (\>=) 38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 7

• Part A: Number of Participants Reporting Any Unsolicited AEs

  An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 28

• Part A: Number of Participants Reporting Any Medically Attended Adverse Events (MAAEs), Serious Adverse Events (SAEs) and AEs of Special Interest (AESIs)

  An SAE refers to any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or extends existing hospitalization, causes persistent or significant disability/incapacity, involves a congenital anomaly/birth defect in a participant's offspring, includes an abnormal pregnancy outcome, or occurs in any other situation per the investigator's judgement. An MAAE results in a visit to a medical professional, such as televisits, physician's office visits, urgent care visits, emergency rooms visits, or hospitalizations. AESIs are severe or non-severe predefined AEs of scientific and medical concern specific to the product/program. This study noted the following AESIs: potential immune-mediated disease (pIMDs), lab-confirmed moderate to severe COVID-19, myocarditis and pericarditis, anaphylaxis, or severe hypersensitivity within 24 hours post-intervention. "Any" indicates the occurrence of the event regardless of its intensity grade.

  Day 1 to Day 181

• Part B: Number of Participants Reporting Any Solicited Administration Site AEs

  Assessed solicited administration site events included injection site redness (erythema), pain, swelling and lymphadenopathy (defined as localized axillary, cervical or supraclavicular swelling or tenderness ipsilateral to the injection arm). Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 7

• Part B: Number of Participants Reporting Any Solicited Systemic AEs

  Assessed solicited systemic events included fever, chills, headache, myalgia (muscle pain), arthralgia (joint pain), and fatigue (tiredness). Fever is defined as body temperature \>= 38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 7

• Part B: Number of Participants Reporting Any Unsolicited AEs

  An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.

  Day 1 to Day 28

• Part B: Number of Participants Reporting Any MAAEs, SAEs and AESIs

  Day 1 to Day 181

Secondary Outcomes (9)

• Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

  At Day 91 and Day 181

• Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

  At Day 91 and Day 181

• Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XZ Spike Protein

  At Day 29, Day 91 and Day 181

• Part A: Percentage of Participants With Seroresponse of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

  At Day 29 compared to baseline (Day 1)

• Part A: Percentage of Participants With Seroresponse of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

  At Day 29 compared to baseline (Day 1)

Study Arms (8)

Part A: CV0701 mRNA COVID-19 Vaccine (Low dose)

EXPERIMENTAL

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the low-dose formulation on Day 1.

Biological: CV0701 mRNA COVID-19 Vaccine (Low dose)

Part A: CV0701 mRNA COVID-19 Vaccine (Medium dose)

EXPERIMENTAL

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the medium-dose formulation on Day 1.

Biological: CV0701 mRNA COVID-19 Vaccine (Medium dose)

Part A: CV0701 mRNA COVID-19 Vaccine (High dose)

EXPERIMENTAL

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the high-dose formulation on Day 1.

Biological: CV0701 mRNA COVID-19 Vaccine (High dose)

Part A: CV0601 mRNA COVID-19 vaccine

EXPERIMENTAL

Participants received one dose of the CV0601 mRNA COVID-19 vaccine on Day 1.

Biological: CV0601 mRNA COVID-19 Vaccine

Part A: Control Vaccine

ACTIVE COMPARATOR

Participants received one dose of the control vaccine at Day 1.

Biological: Control vaccine

Part B: CV0801 mRNA COVID-19 vaccine (Maximum storage condition)

EXPERIMENTAL

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Maximum storage condition.

Biological: CV0801 mRNA COVID-19 Vaccine

Part B: CV0801 mRNA COVID-19 vaccine (Intermediate storage condition)

EXPERIMENTAL

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Intermediate storage condition.

Biological: CV0801 mRNA COVID-19 Vaccine

Part B: CV0801 mRNA COVID-19 vaccine (Baseline-control storage condition)

EXPERIMENTAL

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Baseline-control storage condition.

Biological: CV0801 mRNA COVID-19 Vaccine

Interventions

CV0701 mRNA COVID-19 Vaccine (Low dose) BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0701 mRNA COVID-19 Vaccine (Low dose)

CV0701 mRNA COVID-19 Vaccine (Medium dose) BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0701 mRNA COVID-19 Vaccine (Medium dose)

CV0701 mRNA COVID-19 Vaccine (High dose) BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0701 mRNA COVID-19 Vaccine (High dose)

CV0601 mRNA COVID-19 Vaccine BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0601 mRNA COVID-19 vaccine

Control vaccine BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: Control Vaccine

CV0801 mRNA COVID-19 Vaccine BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part B: CV0801 mRNA COVID-19 vaccine (Baseline-control storage condition); Part B: CV0801 mRNA COVID-19 vaccine (Intermediate storage condition); Part B: CV0801 mRNA COVID-19 vaccine (Maximum storage condition)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

Participants are eligible to be included in the study only if all of the following criteria apply: 1. Is at least 18 years old and has achieved legal age according to local regulations in each participating country. 2. Must provide documented informed consent prior to any study procedures being performed. 3. Can and will comply with the requirements of the protocol, in the opinion of the investigator. 4. Is healthy or medically stable as determined by the investigator's judgment based on medical history, vital sign measurements, and physical examination findings. Participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. 5. Prior receipt of an mRNA COVID-19 vaccine. This may be from a completed primary vaccination series or booster dose(s) of an approved or authorized mRNA COVID-19 vaccine. The last vaccination must be an mRNA COVID-19 vaccination received at least 3 months prior to randomization. 6. If the participant is a woman of childbearing potential, the participant may be enrolled in the study, if they: * have practiced adequate contraception for 30 days prior to study intervention administration; and * have a negative pregnancy test result on the day of study intervention administration; and * have agreed to continue adequate contraception for 2 months after study intervention administration. Female participants of non-childbearing potential may be enrolled in the study. Nonchildbearing potential is defined as current salpingectomy, hysterectomy, ovariectomy, or postmenopausal. Participants are excluded from the study if any of the following criteria apply: 1. Is pregnant or has a positive pregnancy test result at Visit 1. 2. Is breastfeeding or will (re)start breastfeeding from the study intervention administration to 3 months after study intervention administration. 3. Has any medical disease or psychiatric condition that, in the opinion of the investigator, precludes study participation because it would place the participant at an unacceptable risk of injury, would render them unable to meet the requirements of the protocol or may interfere with successful completion of the study. 4. Has any history of an immunosuppressive or immunodeficient condition resulting from disease. 5. Has used immunosuppressants or other immune-modifying drugs for 14 consecutive days or more within 3 months prior to the study intervention administration. Non-systemic corticosteroids are allowed. If systemic corticosteroids have been administered short term (\<14 days) for treatment of an acute illness, participants should not be enrolled into the study until corticosteroid therapy has been discontinued for at least 28 days before study intervention administration. 6. Has an acute medical illness or acute febrile illness with oral temperature ≥38.0°C or ≥100.4°F within 72 hours prior to study intervention administration. 7. Has participated in another study involving any investigational product, vaccine, or device within 28 days before the study intervention administration and/or planned participation through end of study (EoS). 8. Has participated in Part A of this study. 9. Has a history of hypersensitivity or severe allergic reaction including anaphylaxis, generalized urticaria, angioedema, and other significant reactions to any previous mRNA vaccine or any component of the study intervention(s). 10. Has received or plans to receive immunoglobulins or any blood or blood products within 3 months before study intervention administration through EoS. 11. Has a bleeding disorder, or prior history of significant bleeding or bruising following intramuscular injections. 12. Has a history of chronic alcohol consumption and/or drug abuse as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures. 13. Has a history of myocarditis, pericarditis, or idiopathic cardiomyopathy, or presence of any medical condition that increases risk of myocarditis or pericarditis, including cocaine abuse, cardiomyopathy, endomyocardial fibrosis, hypereosinophilic syndrome, hypersensitivity myocarditis, eosinophilic granulomatosis with polyangiitis and persistent myocardial infection. 14. Has received a live vaccine 30 days before the study intervention administration or has a planned administration within 30 days after the study intervention administration. 15. Has received a non-replicating vaccine 8 days before the study intervention administration or has a planned administration within 14 days after the study intervention administration. 16. Has a documented history of confirmed SARS-CoV-2 infection within 3 months before study intervention administration. 17. Has had known close contact with anyone who had a confirmed SARS-CoV-2 infection within 2 weeks before study intervention administration. 18. Is an employee or family member of the investigator or study site staff.

Contact the study team to discuss eligibility requirements. They can help determine if this study is right for you.

Sponsors & Collaborators

• GlaxoSmithKline: lead
• CureVac: collaborator

Study Sites (17)

GSK Investigational Site

Sacramento, California, 95864, United States

Location

GSK Investigational Site

Hollywood, Florida, 33024, United States

Location

GSK Investigational Site

Peoria, Illinois, 61614-4896, United States

Location

GSK Investigational Site

Bruce, Australian Capital Territory, 2617, Australia

Location

GSK Investigational Site

Blacktown, New South Wales, 2148, Australia

Location

GSK Investigational Site

Botany, New South Wales, 2019, Australia

Location

GSK Investigational Site

Brookvale, New South Wales, 2100, Australia

Location

GSK Investigational Site

Coffs Harbour, New South Wales, 2450, Australia

Location

GSK Investigational Site

Darlinghurst, New South Wales, 2010, Australia

Location

GSK Investigational Site

Kanwal, New South Wales, 2259, Australia

Location

GSK Investigational Site

Maroubra, New South Wales, 2035, Australia

Location

GSK Investigational Site

Merewether, New South Wales, 2291, Australia

Location

GSK Investigational Site

Blacktown, Queensland, 4006, Australia

Location

GSK Investigational Site

Sherwood, Queensland, 4068, Australia

Location

GSK Investigational Site

Tarragindi, Queensland, 4075, Australia

Location

GSK Investigational Site

Adelaide, South Australia, 5000, Australia

Location

GSK Investigational Site

Camberwell, Victoria, 3124, Australia

Location

MeSH Terms

Conditions

COVID-19

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Results Point of Contact

• Title: GSK Response Center
• Organization: GlaxoSmithKline

GSKClinicalSupportHD@gsk.com

866-435-7343

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This is an observer-blind study.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 24, 2023
• First Posted: July 25, 2023
• Study Start: August 1, 2023
• Primary Completion: August 30, 2024
• Study Completion: August 30, 2024
• Last Updated: October 23, 2025
• Results First Posted: October 23, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or terminated asset(s) across all indications.
• Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension may be granted, when justified, for up to 6 months.

Locations

US (3); AU (14)